Methods for insomjbilizing coating



Printing presses usually operate at high speeds; the.

more rapid the rate at which. printingv matter can. be produced, naturally the greater the output in. a given period of time or the shorter the time required for. a

given output. For eXampIe neWsprintis generally, passed through presses at about'l6'00'. ft. per minute; and. mag azines and other periodicals which have a definite publication deadline are printed on' high speed presses also. The greatest problem in achieving rapid printing lies in the printing inks. In order to wet paper or textile, glass or metal, or the like, and thus effect arelativel'y lasting impression thereon, ink. must initially be fluid. However, such fluidity is disadvantageous in that, if the printed surface contacts another, surface while. the ink is still'wet, the ink will smear and become blurred or blotted. Further, the ink; once thoroughly dry, should.

become insoluble, so" that'it' will not smear if'the. printed surface should later become Wetted. It is thus vitalfor clear impressions'that the ink be dry and non-tackybefore" the printed surface is" contacted; and that' it' be permanently insolubilized. There isa continuous; search by the trade for methods whereby inks may" be dried and:

rendered permanent more and more quickly;

In the case of newsprint, the porosityof the paper employed allows the ink to be quickly" absorbed" therein. It is because of this that the above-mentioned high print ing speed of 1600 ft; per'minute is possible. case of magazines and other periodicals which use a less porous paper, and in the case of printing on metals, glass, various fabrics. and other less pervious surfaces,

absorption is of little or no aid and possible printing speeds; are materially less. One method generally em ployed to dry or set inks appliedi to such materialsis simpleevaporation of the solvent; often with heat. At

best, this is time-consuming andlcostly. Magazine print' ispassed. over an open flame at temperatures-as h1ghias 650. C., and thesolvent is thus quickly: flash-vaporized;

However, even by this shorter procedure, the.- highest usually obtainable press. speed is about 900 ft; perminute; furthermore, the intenseheat serves;to;weaken: and: generally degrade the fibers of the paper;.resulting in costly web': breaks and shutdowns. Another commercial meth od is to dissolve asolid resin in a solvent and then pres cipitate it from such solution by addition of. a; second? material in which it is" insoluble. Thus, a. resin vehicle may be dissolved in ethylene glycol and mixed with: a.

pigment to form a conventional. ink. This ink may then be impressed on a printing surface. If the impression is brought into contact with water (generally' added as steam), the vehicle will be precipitated from the glycol' solution and thereby insolubilizedl In; such a system the second solvent must be miscible with the first; but" the vehicle must be insoluble in a mixture of the two. Such requirements seriously-restrict the number offsystemspossible; and the rate of insolubilization, even with satisfactory solvent systems, is relatively slow; no really fast drying method utilizing this principle havingbeen developed.

As; will; be. evident, the. problem:. of insolubilizing or rapidly setting, employed in:- various. printing: ape

In the States Patent 0 plications is one of major. importance and-a. great. need exists for a novel procedure whereby suchinks may be more rapidly dried, the. possible. speedoff printing; con

sequently increased}. and7printing. costs, advantageouslylessened. It is among the objects. of. this invention, therefore, to meet this problcm and toprovide novel'. pro.- cedures. for accomplishing such objects. A- particular object is to provide novel means. for rendering ink im pressions upon a printing. surface substantially nonsmearing in character. A specific object is toeffect the rapid and thorough setting, or drying of an. ink fol lowing its application to a printing surface. Other objects and advantages of my invention will be apparent from the ensuing description thereof.

These objects are attained in this invention which broadly comprises accelerating the drying of a pigmented coating composition containing av polymerizable, organic polyhydroxy compound, by subjecting saidcomposition to reaction with. an organic, ester. of a fourth group. metal selected from titanium and zirconium.

In a more, specific and preferred. embodiment, the invention comprises. substantially instantaneously drying an ink composition applied to a paper or other surface by subjecting said: composition (containing a colorant and as a vehicle a polymerizable,. organic polyhydric conium ortho-ester of a primary aliphatic alcohol con-.

taining-from l-8 carbon atoms.

Since the-ihvention is' particularly useful (though not limited) to the quick drying of ink type coating compositions used to produce characters in writing or printing upon a paper or' other suitable surface, it will be described in itsapplication to such adaptation and particularly in printing inks. These are employed for use inthe'usualtype; copper plates, etc., and comprise syrupy, non smudgingi so-called lithographic varnish compositions: exhibiting a suitable consistency and adapted to be readilytransferred from conventional ink rolls to the typeandfrom thetype. to the paper or other surface to which the-.ink' isto' be applied. They consist ofa suitablezlinseed oil and rosin or other oil vehicle in which lampblack or any other suitable inorganic or organic colorant, such; as conventional white or colored pigments or dyestuffs, or mixtures thereof to-obtain various shades or tints; are: incorporated or dispersed. Examples of utilizablea colorants: include titanium dioxide, zinc sulfide;. lithopone; blue: to green phthalocyanines, lead chromateg.vermillion venetian red, cobalt blue, indigo, iron blue Milorijblue,.chrome.-. greens, azo maroons, etc.

The: coating orinkcomposition used, to be effectively useful in accordance: with the invention, must contain, either as a..vehicle1or"as' a component part of the compositiorna polyhydroxy compound such as glycol, glycerol, pentaerythritol,,castor oil, nitrocellulose, etc. Polyhydroxy compounds; having. a; molecular weightv of at least SOO'and. containing. more than one free hydroxyl group.- adapted; to react: with. a titanium. or zirconium ester to.. induce;. quick drying and insolubilization of the composition following its application; to. a. surface are preferred for use; Among examples; of these compounds, thoseofnitrocellulbse, phthalic anhydrideaglycliquid.or can-,bepresent as.a solute. If a solidorsemisolid, .it-.must. b.e capable of beingdissolved in convenventionalorganicsolvents inaccordance with customary. printing: practices If. a liquid, it; should: polymerize to a solid, or if asolnbleisolidtin should-polymerizeto en 'Patented Jan. 31, 1956 Y insoluble form. It can be incorporateddirectly in the vehicle or'composition to form a component part of each; or, if preferred, the vehicle can consist ventirely of the compound or be composed of suitable mixtures of polyhydroxy compounds. Thus, where a solid or semi-solid form 'is used, resort can be advantageously had to a polyhydroxy compound type solvent, such as glycerin or glycol, etc., to effect dissolution and subsequent use in such solvent. In such instance the metal ester will react with both the vehicle and solvent to produce an insoluble ink film comprising a polymer of vehicle plus solvent plus ester. If desired, more than one vehicle can be used in a given composition, as may various mixtures and eombinations'of utilizable vehicles and solvents.

The polyhydroxy compound-containing ink or like coating composition, upon being conventionallyimpressed upon a surface as by transfer from, for example, an ink roll to a paper, textile, glass, metal, etc., is immediately subjected to contact with, preferably, a stoichiometric quantity of a contemplated metal ester. Those found to be of particular value for use in the invention comprise the organic esters of titanium or zirconium. Surprisingly, all metal esters are not satisfactory foruse herein since silicon esters, for example, prove of little or no value for use. It appears that the desired insolubilization and rapid set of polyhydroxy vehicles is attained only with esters of metals which have a coordination number higher than their valence. Thus, zirconium and titanium have coordination numbers of 6, while silicon has a coordination number of 4. In practice, essentially any titanium or zirconium ester (or alcoholate) or mixtures of such compounds can be used in the invention. They are readily formed by replacing a hydroxy hydrogen of an alcohol with titanium or zirconium. One useful method of preparation comprises reacting an alchol with a halide, preferably the chloride, of titanium or zirconium in the presence of ammonia, and in accordance with theprocedures of U. S. Patent No. 2,187,821. Because of their availability and commercial attractiveness, use'is preferred of titanium or zirconium ortho esters of alcohols having from 1-8 carbon atoms in their primary chains; e. g., methyl, butyl, secondary butyl, propyl, isopropyl, tertiary-butyl, ethyl, amyl, and like esters, substituted or unsubstituted. Representative esters of such compounds include ethyl titanate, butyl titanate, octyl titanate, phenyl titanate, phenyl ethyl titanate, and cyclohexyl titanate, etc., as well as the zirconates of these representative titanates. As in the case of the polyhydroxy vehicle, the ester may be employed in the form of a liquid or solution, or, if a solid, it may be dissolved in a suitable anhydrous solvent prior to use. In the latter instance, a solvent which also tends to insolubilize the particular polyhydroxy vehicle present is especially satisfactory, giving a combined and accentuated setting effect. Such contact of the ester with the coating composition can, for example, be effected by superimposing the ester upon the ink or other coating impression through overprinting, rolling or spraying, or by immediately subjecting the printing surface to a vaporous atmosphere of the ester while an elevated temperature condition prevails over such coated surface. In the latter instance, any alcohol or like byproducts which form are readily removed as vapors.

In the interaction between the ester and organic compound, the latter is substantially instantaneously polymerized to render the ink or coating insoluble in either water or 'oils. The insolubilization occuring within one second or less, depending upon the particular polyhydroxy compound and ester utilized, results in a non-tacky print even before solvent evaporation to obviate the necessity of employing open-flamevaporization or other solvent .removal methods and enable resort to a much less complex and generally more rapid printing operation. Additionally, the print, whendry, will not set off from the paper or. other surface to which it is applied.

in which R represents an alkyl, alkenyl, aryl, alkaryl, or

arylalkyl grouping, x is at least 2 and preferably at least 3, Y is a polyfunctional organic radical, and Z is an integer greater than 1. The reaction shown is between a titanium ester of a monohydroxy organic compound, e. g., an alcohol and a polyhydroxy compound which may be represented by nitrocellulose or partially-hydrolyzed polyvinyl acetate. The reaction may of course proceed even further, and there may be various modifications and other chemical compounds formed. While polymerization and consequent insolubility can be achieved with practically any polyhydroxy vehicle, proper selection to fit the particular objective is recommended. For instance, glycerol may be reacted with a titanium or zirconium ester and will set rapidly but optimum results are not achieved in certain instances since the product tends to flake on of non-porous surfaces so that a relatively permanent impression upon such surfaces may not be obtained. On the other hand, a phthalic anhydrideglycerol resin of low molecular weight, though also utilizable and providing satisfactory binder action, tends to set up slowly in such applications and hence is not preferred for use where the highest setting speed is desired limitation of such invention, are given:

Example I 10 parts by weight of a 30% by weight solution of nitrocellulose in n-butyl acetate were mulled after preparation with one part of lampblack. The resulting ink was then impressed upon paper by means of a rubber stamp. Meanwhile, butyl zirconate was dissolved in toluene to provide a 50% by weight solution. Immediately after stamping the paper with the ink, the zirconium ester solution was applied thereover by means of a rubber roller. Immediately following such application, setting of the ink was tested by the simple expedient of rubbing the impression with the hand. It was found that within one second after the ester treatment the ink was completely dry and non-smearing, even though the experimenters hand was moist and rather oily during the test. In a comparable experiment but in which ester treatment was not resorted to, smearing occurred after the lapse of seconds time.

Example 11 by directly contacting the printed surface with the evolved vapors. It was found that the ester treatment thus efiected permanently insolubilized the ink within one agzsezoa.

second, .in.-contrast.to a.50.01second-period for: insolubiliza-- tion. where ester treatment. was-.notaused;

' Example-III Asoylbean. oil-modified alkyd. resin wherein the, source. of hydroxyl groups was unesterified or. excess glyceriru, was; dissolved in; 'xylol. to. provide. a. 49.2% by weight solutionasan ink vehicle. 0.7 partby. weight. of lamp? blaek was: incorporated. in .partsof. this. resin. solutionto..-.provide an. ink. composition. Tertiary-butyl. titanate. (itself; a. liquid)- was. applied. to. a. printing surface means. of: a roller. Immediately after. such. application, the. prepared. ink was. superimposed. on such. surface: by. conventional overprinting. As a result,. therate of. set!- ting of. the ink. under. these. conditions was. found. to: be extremely. rapid, being ,markedly less. than one: second.

Example IV" An: ink. was prepared. by. incorporating. 0.3. part. by weight. of:lampbl ack.in; 10 parts by weightofa. 64.4% solution of. a. caster. oil-modified. alkyd resin in. xylolt.

' (This alkyd had a higher percentage. of; oil modification than; the alkyd ofz Example II, but a: lower. free hydroxyl content.) Au impression madeby'. this ink.on aprinting.

surface was then. insolubilized in. about one second. when.

sprayed. with av toluene solution. of n-amyl. zirconate.

Example V" A. 64.7% by weight solution in mineral. spirits. of a.

pentaerythritol alkyd resin (the free. hydroxyl groups. of. whichv wereofthe primary alcohol type was-prepared, followingwhich- 10 parts. by weightofthis. solution were.

resulting print being. then; immediatelysprayed. with. liquidn-propyl; titanate". Therink. impression was found. to.set-in;about 3; seconds, in contrasttoa SOD-second sets ting period when the titanium ester was. notv employed;

Example VI- An ink similar to those ofi thepreviouszexampleswas.

prepared, by utilizing as the vehicle: a. 44.0% weight solution: of. a bisphenolrepichlorhydrin. resin in minerah spirits and .7- part. by weight of.1ampblack;. This. ink

was cohventionally impressed: upon a printing; surface: and was then contacted with vapors of isopropyl titanater Reaction between the ester'and the ink vehicle proceeded rapidly, the ink becomingrpolymerized and. permanently insoluble in about..0.5 seconth lna-compa-rable experiment, but in which ester treatment to efiect insol-ubilizationwas not resorted to; setting and drying of? the? ink did not' take place until the lapse of 200 seconds.

Example VII A dehydrated castor oil-modified resinwas dissolved in xyl'olto give about a 50%- solids content in the solution; A conventional ink wasprepared with this material. and used'inprinting. The resulting'print was contacted withliquid ethyl titanate by rolling the latter" across the sur* face. The ethyl titanate treatment caused the ink to set inbetween Mr and /2 second, in contrast to a 500- second period whereestertreatment was not resortedto.

1 As shown in the examples, the invention possesses "thoroughly'mixed. with 0.13. partof. lampblack to. form; anzink; This: ink wastprinted upon a paper. surface, the:

titanates or. zirconates .such: as. ethyl isopropyl,v butyl. or.

octylititanatesor. zirconates,,which,.as. already stated-, can be. applied int the. fluid. condition, i.-. e., .v vapors or as liquids, to the. printed. or. decorated. surface.=.

The. invention is: useful in. almost. anytype of printing;

and on widely different; surfaces. The'achievementoi rap-id. set makesit particularly. valuable for paper printing where high speed. presses are. used; andfor impres--' sions on. metals and. glass. where present. drying; methods are. disadvantageousl-yslow and. clear. printtisdifiicultfto obtain.v It is also. valuable for. impressing designs and:

printingupon. textile and. otherfabric. surfaces. In. this field, also, potential. rapid-setting, is a: desired advance:- in. the. art- The impressions resulting, from: process: are substantially non-smearing, and insoluble, not only.

inwaterfbutalso.irrzoilmandorganic.solvents. The disadvantage .ofpresentpaper inks. isoften' thatoil from .the finger or hand will. cause; the..;.inki to smudge jand a; disa advantage ofi'fabric :inksris .thatthey. are-not. oftenwholly stable in. the. presence: of solvents. used; indry-cleaning;

The ink films insolubil-ized by;- the; present: metal ester treatment .will .be found. to. overcome these disadvantages.

It..will be seen fromithetaboventhatmany interrelated factors. are. to. be considered. in operating the. present process, Thus, the: binding quality of.the.:insolubilizedvehicle. and the rapidity of its. setting or drying are inter dependent with the particular vehicleand ester chosen.- Also. of importance. are. the. temperatures. employed, the

particular. methods; ofprint: application. or transfenthe surface. onwhichtheink. impression is being; made, etc. 7 Additionally, consideration should be. given tothe relative proportions--of ester. and vehicleused: Obviously,

if. lessthan aistoichiometric quantity of ester isemployed.

incomplete :reaction: and.- incomplete. or. slowersetting; may occur. It sometimesgha-ppens, also, that. excess. ester tendsrto slow the: setting rate. Henceit may be. hypothecatedi thattsuch. excessserves. as.- a. solvent. for the supposedly. insoluble.- product' and hydrolysis. proceeds more slow-1%,, or thattoo manymetal gmups; bymassaction actually allow lessxpolymerization and crossglinking. The. viscosity of thevehicle. may; also; be-.afactor? in: itsesetting,

properties. If the-ink. is.rel-atively thick-",the. surface may. react immediately, when; the. ester contacts. it,. while-the. underneath or' unexposed area may remain unafiected. Under; any circumstances, the elevation'of. the-.temperature'. will. be. found to'speed the; reaction and the; rate.- of set;. The effect; of. relatively; mild. heat. is; probably not simply. to.- evaporatethe solvent, as.v for instance in. the.

CE'SG'JOJ. the extremes heat= of. the open-flame process; but rather also tor accelerate the chemical. reaction; between the'vehicIe, and-:the. ester.

Many; varied. methods. on. applying: the vehicle and the. esterto theprinting surface; are possible. As. indicated the pigmented vehicle or ink is generally first. impressed: upon: as suriaeeby: any known; or. desired .processand the ester isxthen superimposed on the-resulting ink impression; where feasible, itmayalternatively. be introduced tothersurface in-vaporous; form. Although this. described. order of. addition. is generally preferred, such. order. maybe reversed, if desired, whereby the-metal ester is applied first. to the. surface and. the. vehicle. then. superimposed thereon. It is'. sometimes. satisfactory and feasible, too, to: employ, the. present process. in. conjunction withthe.

prior art. methods. Thus, the .openrflame processfor printing of paper can be used with my ester treatment, or. the.

procedureof insolubilization withasecondsolvent can be resorted to. The-combined eifeetof my treatment withpresent commercial methods will sometimes. serve to achieve even greater. printing. press speeds, or a lower necessary temperature for flash-vaporization, rendering it.

possibletoobtain as clear and acceptable print-with aless.

expensive; lower-grade paper.

I claim as my invention:

1.. A: methodfor. insolubilizing and.- rapidly' setting; a printing j ink. coating. composition applied. to. a surface comprising reacting a polymerizable, polyhydroxy organic compound in-said coating while in liquid condition with a stoichiometric amount of an organic ester of an aliphatic monohydric alcohol containing from 1-8 carbon atoms of a metal selected from the group consisting of titanium and zirconium in the presence of said coating. 7

2. A process for accelerating the drying of a colorimparting ink coating composition containing as an essential ingredient a polymerizable polyhydroxy organic compound in the liquid state which comprises contacting said coating in its applied state to a surface and reacting said compound with a stoichiometric quantity of an organic ester of an aliphatic monohydric alcohol containing from 1-8 carbon atoms of a metal selected from the group consisting of titanium and zirconium.

3. An improved process of insolubilizing a polyhydroxy compound-containing ink coating composition on a surface to which it is applied which comprises reacting said compound in liquid state with a stoichiometric amount of an organic ester of an aliphatic monohydric alcohol containing from 1-8 carbon atoms of titanium.

4. An improved process of insolubilizing a polyhydroxy compound-containing inkcoating composition on a surface to which it is applied which comprises reacting said compound in liquid state with a stoichiometric amount of an organic zirconium ester of a monohydric alcohol containing from 1-8 carbon atoms.

5. A process for accelerating the drying of an ink composition which comprises applying a pigmented ink composition containing an organic polyhydroxy compound to a printing surface and reacting the resulting ink impression while in liquid state with a stoichiometric amount of an organic ester of an aliphatic monohydric alcohol containing from 1-8 carbon atoms of a metal selected from the group consisting of titanium and zirconium.

6. A process for producing substantially non-smearing ink impressions upon a surface which comprises applying to said surface an ink compositioncontaining a colorant and a polymerizable polyhydroxy organic compound and prior to drying said composition polymerizing said compound in situ by reaction with a stoichiometric amount of an organic ester of an aliphatic monohydric alcohol containing from l-8 carbon atoms of a metal selected from the group consisting of titanium and zirconium.

7. A process for quickly drying a printing ink which comprises applying a pigmented printing ink composition containing as an essential ingredient a polymerizable polyhydroxy organic compound having a molecular weight of at least about 500 to a printing surface, and thereupon reacting said compound while in liquid state with a stoichiometric amount of an organic metal ester of an aliphatic monohydric alcohol containing from one to eight carbon atoms selected from the group consisting of titanium and zirconium.

8. A process for drying and insolubilizing a printing ink which comprises impressing upon a printing surface a pigmented ink composition containing as a vehicle a polymerizable polyhydroxy organic compound having a molecular weight of at least about 500, and insolubilizing said compound while in liquid state upon said surface within one second by reacting it with a stoichiometric amount of a metal ester of a primary aliphatic alcohol containing from one to eight carbon atoms, said metal being selected from the group consisting of titaniumand zirconium.

9. A process for drying and insolubilizing a printing ink which comprises impressing upon a printing surface a pigmented ink composition containing as a vehicle a polymerizable polyhydroxy organic compound having a molecular weight of at least about 500, and insolubilizing said compound while in liquid state upon said surface within one second by reacting it with a stoichiometric amount of isopropyl titanate.

10. A process for drying and insolubilizing a printing ink which comprises impressing upon a printing surface 8 a'pigmentedink composition containing as a vehicle a polymerizable polyhydroxy organic compound having a molecular weight of at least about 500, and insolubilizing said compound while in liquid state upon said surface within one second by reacting it with a stoichiometric amount of isopropyl zirconate.

11. A process for drying and insolubilizing a printing ink which comprises impressing upon a printing surface a pigmented ink composition containing as a vehicle a polymerizable polyhydroxy organic compound having a molecular weight of at least about 500, and insolubilizing said compound while in liquid state upon said surface withinone second by reacting it with a stoichiometric amount of ethyltitanate.

12. A process for drying and insolubilizing a printing ink which comprises impressing upon a printing surface a pigmented ink composition containing as a vehicle'a polymerizable polyhydroxy organic compound having a molecular weight of at least about 500, and insolubilizing said compound while in liquid state upon said surface within one second by reacting it with a stoichiometric amount of butyl titanate.

13. A process for drying and insolubilizing a printing ink which comprises impressing upon a printing surface a pigmented ink composition containing nitrocellulose as a vehicle, and insolubilizing said ink composition in liquid state on said surface within. one second by reacting the nitrocellulose with a stoichiometric amount of a titanium ester of a monohydric alcohol containing from 1-8 carbon atoms.

ink which comprises impressing upon a printing surface a pigmented ink composition containing bisphenol-epichlorhydrin as a vehicle, and insolubilizing said ink in liquid state composition on said surface within one second by reacting the bisphenol-epichlorhydrin with a stoichio-- References Cited in the file of this patent UNITED STATES PATENTS 1,752,462 Smith Apr. 1, 1930 1,900,603 Coolidge Mar. 7, 1933 1,933,520 Bruson Oct. 31, 1933 2,109,774 Hooft Mar. 1, 1938 2,116,321 Minich May 3, 1938 2,132,997 Plechner Oct. 11, 1938 2,187,821 Nelles Jan. 23, 1940 2,208,587 Kienle July 23, 1940 2,258,718 Rothrock Oct. 14, 1941 2,518,193 Signaig a Aug. 8, 1950 I 2,518,607 Erickson Aug. 15, 1950 2,528,850 Thorp et al. Y Nov. 7, 1950 2,613,162 Chatficld Oct. 7, 1952 FOREIGN PATENTS 346,812 Great Britain Apr. 17, 1931 513,222 Great Britain Oct. 6, 1939 OTHER REFERENCES Ellis: Printing Inks. Published 1940 by Reinhold Publishing Co., N. Y. Only page cited.

Minich: The Anionics of Driers. Presented February 15, 1950. Published in Oflicial Digest, July 1950, pp. 53 to 540. Only pp. 533 to 535 relied on.

Minich: The Anionics of Driers. Previously cited. Pages 536 and 537 added. 7

14. A process for drying and insolubilizing a printing 

1. A METHOD FOR INSOLUBILIZING AND RAPIDLY SETTING A PRINTING INK COATING COMPOSITION APPLIED TO A SURFACE, COMPRISING REACTING A POLYMERIZABLE, POLYHYDROXY ORGANIC COMPOUND IN SAID COATING WHILE IN LIQUID CONDITION WITH A STOICHIOMETRIC AMOUNT OF AN ORGANIC ESTER OF AN ALIPHATIC MONOHYDRIC ALCOHOL CONTAINING FROM 1-8 CARBON ATOMS OF A METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ZIRCONIUM IN THE PRESENCE OF SAID COATING. 